TM 5-3825-226-24
AIR SYSTEM AND BRAKE SCHEMATIC FOR WATER DISTRIBUTOR
1. Air line from brake valve on tractor. 2. Brake oil line to right wheel brake. 3. Quick release
valve. 4. Air chamber and master cylinder. 5. Residual pressure valve (check valve). 6. Brake oil
line to left wheel brake.
AIR FLOW
Compressed air goes from the air tanks to the brake
control valve, seat suspension valve, horn valve, low air
pressure buzzer, air pressure gauge, parking brake
valve and emergency brake valve.
Air from the brake control valve's lower chamber
goes to the water distributor brake chamber. Air from
the brake control valve's upper chamber goes to the
tractor brake chamber. The tractor and the water
distributor have air activated hydraulic brake systems.
The brake systems are not connected together.
OIL FLOW
The hydraulic brake system for each part of the
machine has its own master cylinder, brake lines and
caliper assemblies. Each master cylinder has its own
fluid reservoir, and the maintenance for the level of the
fluid must be done separately. As the air chamber rod is
extended, it pushes the master cylinder piston. Piston
movement sends oil through the lines into the caliper
assemblies. At each caliper the oil pushes on the back
of the pistons and the pistons push the friction pads
against the brake discs.
When the brake pedal is released, the air pressure
against the brake master cylinder is relieved (let out).
The master cylinder piston is retracted and hydraulic oil
pressure is let off of the caliper pistons. The residual
pressure valves (check valves) keep a 3 to 6 psi (20 to
40 kPa) back pressure on the pads to keep them against
the discs. The pistons and pads are not returned by
springs. They just release their grip on the disc. The
pads do not move away from the discs so no adjustment
is needed when the pads begin to wear because the
pads keep a little contact with the discs, the pads keep
the discs clean.
SEAT AIR SUSPENSION
Push on the control valve to increase shock
absorber charge. Pull on the control valve to decrease
shock absorber charge.
CONTROL VALVE FOR SEAT SUSPENSION
2-129
